Die-casting mold



HQA. ADAMS DIE CASTING MOLD Filed April 12- 1927 Fge@ - tremity of the gate.

Patented Nov. 13, 1928.l

UNITED STATES PATENT OFFICE.

HARRY A. ADAMS, OF ROCHESTER, NEW YORK, ASSIGNOR TO NORTH ,EAS'IL` ELECTRIC I COMPANY, OF ROCHESTER,'NEW YORK, A CORPORATION OF NEW YORK.

DIE-CASTING MOLD.

Application led April 12, 1927. Serial No. 183,208,

This invention relates particularly to the form of the gate and the core by which the solidified gate metal is separated from the molten metal in the supply passage or nozzle of a die-casting machine.

In separating the cast metal from the supply, it is very important that no portion of the solidified metal in the gate of the mold be permitted to remain when the casting is removed from the mold, for any such remaining metal will be torced into the mold at the next casting operation and will prevent proper filling of the mold. It has accordingly been customary to use a gate of a more or less tapered or conical form, and to provide the mold with a metal core projecting downwardly into the gate. This core, at its lower extremity, has only sufficient clearance from the sides of the gate to permit the entrance of the metal, and the extremity of the core coincides with the narrowest extremity of the gate. Adhesion between the solidified gate metal and the core is depended on to cause the core to withdraw the gate metal and part it from the molten supply metal at the narrow eX- It has been found, however, that the construction just described does not always act as intended, since there isv no'definite point of demarcation between the molten metal and the solid metal, and it frequently happens that the metal parts somewhat above the extremity of the core, leaving solid metal within the gate.

The object oi the present invention is to produce a die-casting mold, of the type in question, in which the form ot' the core and its relation to the gate are so modified as to avoid the defective operation just described. The inventor has discovered that the adhesion between the solid metal and the core is greatly enhanced if the core is caused to it closely against the inner surface of nthegate at its lower extremity, while apassage for the admissiondofthe metal is formed by one ,or more slots cut laterally intothe side of the core and extending to its lower extremity, and that by this modification the desired result is secured.

In the accompanying drawings, Fig. l is a sectional side elevation showing a mold embodying the present invention, together with the nozzle plate of a die-casting machine upon which it is mounted. Fig. 2 is a side elevation of the core of the mold, as seen from the right or the left of the position which it occupies in Fig. l, and Fig. 3 is a bottom end view of the core.

The invention is illustrated as embodied in a mold having upper 'and lower members or dies 5 and 6, with a mold cavity 7 formed between them. The general form and structure of the die members and the form of the mold cavity are of no importance so far as the present invention is concerned. The lower die 6 is shown as provided with a nozzle S fitting an opening in a nozzle plate 9, and it will be understood that this plate forms a part of a chamber or'passage containing the molten metal which is to be injected, in the usual manner, through the nozzle into the mold.

The lower die 6 is provided with the usual gate 10, of downwardly tapered or conical iorm, the lower extremity of this gate communicating with the upwardly conical passage in the nozzle 8. The upper die 5 is provided with a core 11 occupying the central part of the gate, and this core, unlike those heretofore used, 'is provided with a cylindrical lower portion l2 of such diameter that it fits closely within the lower extremity of the gate, thus providing a. positive parting between the gate metal and the supply metal at this point. To provide, however, for the admission of metal from the nozzle to the ate, the core is transversely slotted in its lower portion, thus forming a passage 13 with parallel side walls. This passage is shown as comprising, in effect, two opposite lateral slots which merge into one atA the bottom. It is not, however, necessary to slot the core from both sides as shown.

It has been found that the solidified metal within the slot 13 clings irmly to the core and always separates cleanly from the m01- ten supply metal in lthe nozzle.

The invention claimed is:

A de-casting mold, of the type comprising a die provided With a gate and a die provided With a core extending into said 5 gate and forming, therewith, a narrow annular passage for molten metal, characterized by the fact that the extremity of the core fits closely Within the extremity of the gate, and the core` has a longitudinally extending slotforming a passage into the gate beyond the point at which the parts are so fitted.

' HARRY A. ADAMS. 

